"It sure doesn't seem like there is much of anything doing here,"

whispered Buckhart. "I hope we haven't arrived too late, pard."

"The only way to find out about that is to investigate," returned d.i.c.k, in the same cautious tone.

They approached the mill, circling a last spot where the moonlight shone down through the trees.

True, their hearts were beating faster than usual in their bosoms, but they were fully as undaunted as when they had set out from Robin Hood's Tavern.

The old mill was reached at last, and they listened as they stood close beside its rotting wall.

No sound came from within.

"Have you the candles, d.i.c.k?" asked the Texan.

"Sure," was the a.s.surance. "But we'll not use them until we get inside."

They tried the door, but it was fastened, and after a few moments they decided that it could not be opened from the outside unless the person who attempted it knew how.

"We'll have to find a window that will let us in," said d.i.c.k, in a whisper.

Fortunately, they had little difficulty about this, for the windows of the mill were broken, and, although they had been boarded up, the boards were torn away from one of them. This window was high, but d.i.c.k mounted on Buckhart's shoulders and crept through it. Then he leaned far out and grasped the hands of the Texan, who followed him, but made more or less noise in scrambling up and over the sill.

"Hush!" warned d.i.c.k. "We'll listen here a while to see if we have disturbed any one."

The silence within the place was even more oppressive than that of the dark woods outside.

"I sure am afraid we're on a Tom Fool's errand, partner," murmured Buckhart. "I'm almost ready to bet my boots that, besides ourselves, there's no living thing in this thundering old building."

"You may be right," d.i.c.k admitted; "but we'll search it from top to bottom before we quit. I hate to think that, in the face of almost certain death, Luke Durbin lied to me."

"Mebbe he didn't lie; mebbe Bunol changed his plan after that runaway and smash-up."

"Perhaps so."

"Light a candle, pard."

"Not yet. We'll prowl round a little first. Take care not to step into a hole or trap of any sort."

They moved forward with the utmost caution, feeling their way along in the darkness. Soon they found a door that was standing wide open and pa.s.sed into a sort of hall, beyond which another door opened into another part of the building, which d.i.c.k believed was the mill proper.

In spite of their caution, they had made some slight noises, Brad once striking the toe of his boot against some obstacle.

As they paused there in irresolution, something of a startling nature took place.

First through the empty hallowness of the vacant rooms echoed a groan that was most dismal and nerve-trying.

This sound was followed almost instantly by a shrill, piercing shriek, like that which might be uttered by some one in the agony of death!

Buckhart afterward confessed that his hair "certain rose up on its hind legs and mighty nigh kicked his hat off."

No wonder.

Such appalling sounds breaking in on the absolute silence of the place were enough to give a man of iron something more than a slight start.

The sounds died out as suddenly as they had broken forth, and the stillness that followed was disturbed only by the tumultuous beating of the hearts of the two boys.

Brad clutched d.i.c.k's arm.

"Great everlasting tornadoes!" groaned the Texan. "That sure was letting it out some!"

"Just a little!" admitted d.i.c.k.

It did not take the boys long to recover from the shock, which was followed by a feeling of resentment, for both knew some one had sought to frighten them in that manner.

Neither of them believed in ghosts.

"Wherever did it come from, pard?" asked Buckhart, softly-"upstairs or down?"

d.i.c.k was compelled to confess that he did not know. The groan and the shriek had echoed through the empty rooms in a most deceptive manner.

By this time both lads had their revolvers ready for use.

They remained perfectly still for many minutes, listening for some new sound to guide them. Although they were wonderfully courageous, they knew they might be plunging into a deadly trap, and neither cared about throwing his life away.

Still they had come there for the purpose of trying to rescue Professor Gunn, and they did not propose to retire without doing their best to accomplish their design.

Finally they decided to investigate the upper portion of the mill, and on their hands and knees they crept up the stairs. They knew not what moment they might be attacked, and when they reached the top of the flight they more than half expected to be set upon without further delay.

After the startling sounds which had chilled and appalled them for a few moments, there was no further demonstration, and the deathlike silence of the place placed another strain upon their nerves, which seemed to grow more and more severe. Finally they felt that they would gladly welcome a noise of some sort.

The moonlight reached some of the upper windows of the building now, and it a.s.sisted them in exploring a portion of that floor. But though they went from room to room, they found up there no sign of any living thing.

"This is a whole lot disappointing, partner," breathed the Texan. "There is nothing doing up here."

"Evidently not," admitted d.i.c.k. "Let's go down. We have not half investigated the rooms below."

They still believed it quite probable they would be attacked while in the old mill, but neither faltered. Down the stairs they went, and d.i.c.k led the way into that part of the building that had once been the mill proper.

Suddenly he stopped in the dark and put out his hand, checking Brad.

"Don't move!" he warned.

"What's the matter?"

d.i.c.k had heard the sound of running water rising from almost directly beneath his feet, and a cold breath of air came up and smote him in the face.

"Keep your revolver ready for use," he said. "I'm going to light a candle."